Panelboards and load centers used in electrical distribution systems typically include a deadfront, door, trim or other type of cover which is mounted to an enclosure. The cover is typically fabricated from sheet metal and includes removeable sections known as twistouts each of which, when removed, provide an opening for a handle of a device such as a circuit breaker to enable operation of the circuit breaker.
The twistouts are generally configured as rectangularly shaped sheet metal blanks. Each twistout is attached to the cover by a metal tab. During installation, the twistouts are manually removed from the cover by a contractor or electrician by repeatedly bending or twisting the metal tab until the tab breaks thus separating the twistout from the cover and forming an opening. This allows the circuit breaker handle to protrude through the opening and enables assembly of cover to the panelboard enclosure. Removal of the twistouts is a difficult and labor intensive operation and requires the use of special tools.
A panelboard may be configured as either a main lug panelboard or a main breaker panelboard each having different cover configurations. In particular, the cover used in a main breaker panelboard includes an opening for accommodating a breaker handle whereas the cover used in a main lug panelboard does not have the opening. Therefore, manufacturers typically provide two different types of covers in order to accommodate each panelboard configuration.
During on-site installation of an electrical distribution system, it is frequently desirable to convert a cover originally configured for a main lug panelboard to a cover which is suitable for a main breaker panelboard. This requires that an opening be manually cut into the main lug cover by an installer. However, this is also labor intensive and in many instances cannot be done in the field. In order to facilitate the conversion, manufacturers also supply covers having a twistout section for creating an opening in the cover. These types of covers may be used in either a main lug panelboard configuration wherein the twistout is left in place, or in a main breaker configuration wherein the twistout is removed to form an opening for accommodating a breaker handle. As previously described however, removal of a twistout is a difficult and labor intensive operation and requires the use of special tools.
Therefore, there is a need for a cover which reduces the amount of labor needed to form openings for accommodating a handle of a device, such as a circuit breaker, and wherein the opening may be formed without the use of special tools.